How severe is CVE-2021-26731?

CVE-2021-26731 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-26731 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (84th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-26731?

CVE-2021-26731 affects Lannerinc Iac-ast2500a Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-26731?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2021-26731 published?

CVE-2021-26731 was published on 2022-10-24 and last updated on 2026-06-17.

CVE-2021-26731

CVE-2021-26731 is a critical-severity vulnerability in Lannerinc Iac-ast2500a Firmware with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-77.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 2% (84th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-77
Affected product: Lannerinc Iac-ast2500a Firmware
Published: 2022-10-24
Last modified: 2026-06-17

Description

Command injection and multiple stack-based buffer overflows vulnerabilities in the modifyUserb_func function of spx_restservice allow an authenticated attacker to execute arbitrary code with the same privileges as the server user (root). This issue affects: Lanner Inc IAC-AST2500A standard firmware version 1.10.0.

Frequently asked questions

What is CVE-2021-26731?: Command injection and multiple stack-based buffer overflows vulnerabilities in the modifyUserb_func function of spx_restservice allow an authenticated attacker to execute arbitrary code with the same privileges as the server user (root). This issue affects: Lanner Inc IAC-AST2500A standard firmware version 1.10.0.
How severe is CVE-2021-26731?: CVE-2021-26731 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-26731 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (84th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-26731?: CVE-2021-26731 affects Lannerinc Iac-ast2500a Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-26731?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2021-26731 published?: CVE-2021-26731 was published on 2022-10-24 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:lannerinc:iac-ast2500a_firmware:1.10.0:*:*:*:*:*:*:*

More vulnerabilities in Lannerinc Iac-ast2500a Firmware

CVE-2021-26730 — Critical (CVSS 10.0): A stack-based buffer overflow vulnerability in a subfunction of the Login_handler_func function of spx_restservice…
CVE-2021-26729 — Critical (CVSS 10.0): Command injection and multiple stack-based buffer overflows vulnerabilities in the Login_handler_func function of…
CVE-2021-26728 — Critical (CVSS 10.0): Command injection and stack-based buffer overflow vulnerabilities in the KillDupUsr_func function of spx_restservice…
CVE-2021-26727 — Critical (CVSS 10.0): Multiple command injections and stack-based buffer overflows vulnerabilities in the SubNet_handler_func function of…
CVE-2021-44776 — Medium (CVSS 6.5): A broken access control vulnerability in the SubNet_handler_func function of spx_restservice allows an attacker to…
CVE-2021-26732 — Medium (CVSS 6.5): A broken access control vulnerability in the First_network_func function of spx_restservice allows an attacker to…

All CVEs affecting Lannerinc Iac-ast2500a Firmware →

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